Waste material inflow into resource limited landfills is strained by the voluminous amount of post consumer carpet waste produced by carpet distributors and carpet installation contractors and post industrial carpet waste produced by carpet manufacturers. Post industrial carpet waste can include, for example, commercial, industrial and residential carpet waste; manufacturing remnants; quality control failures, and the like. Post consumer carpet waste can be, for example, used carpet, e.g., carpet removed from a home, apartment complex, or a commercial installation, or unused carpet, e.g., residual carpet left from an installation or manufacturing process. While most estimates indicate that carpet waste constitutes only 1 to 2% of all municipal solid waste, this amount still represents a vast quantity of waste that can have a substantial economic and environmental impact.
The carpet waste inflow into landfills is not generally environmentally beneficial. In an effort to mitigate the amount of carpet waste that is shipped to landfills, efforts are being made to manually recycle at least a portion of the carpet waste prior to insertion into the landfill waste stream. Recycling carpet, however, is difficult because its major components are chemically and physically diverse. Most carpets comprise about 20-50 percent weight face fiber, the remainder being backing materials, commonly polypropylene, and an adhesive which attaches the carpet fiber to the backing material. The adhesive typically comprises a carboxylated styrene-butadiene (XSB) latex copolymer, and inorganic filler like calcium carbonate. Because of these difficulties, the amount of carpet reclaimed through recycling operations to date is limited, and only a minimal percentage of the total carpet waste may be useful in the production of green technology products. Accordingly, there is a need for efficient recycling of post industrial and post consumer carpet waste to reduce the amount of waste being disposed of at landfills.
Most carpet recycling methods to date have focused on recycling certain environmentally malignant constituents of carpet. Examples include polymers, such as nylon, and adhesive constituents found in carpet waste. However, little attention has been devoted to the various other constituents of carpet, such as inorganic filler. While such constituents may not present a direct environmental harm, they nonetheless represent a potential cost savings and a reduction in landfilling burden. If such materials could be reclaimed and recycled, the supply of such materials could be augmented, thereby reducing the burden to manufacture new materials. In addition, such broad-based recycling methods can also potentially help to comport with National Sanitation Foundation (NSF) 140/2007 recommendations, which encourage carpet industries to develop sustainable carpet manufacturing and recycling programs for social, economic, and environmental benefits.
Generally, carpet manufacturers use steam, electricity or other energy sources in their manufacturing processes. Energy may be purchased directly (electricity, for example) or produced from a number of processes and energy sources, such as coal or natural gas (steam, for example). However, conventional energy production processes may be relatively inefficient and/or environmentally unfriendly. Accordingly, there is a need for production of required energy for carpet manufacturers that is derived from post industrial and post consumer carpet waste that would otherwise be diverted to landfills. In addition, the conversion of post industrial and post consumer carpet waste into energy will result in cleaner emissions when compared to the consumption of coal. Moreover, by utilizing diverted carpet material, carpet manufacturers can reduce and stabilize steam production costs significantly. Further, there is a need to provide improved carpet recycling methods and systems that can yield reclaimed materials suitable for use in the manufacture of new carpets and like materials.